Screen shot by J Kyrnin
Overture
It can be hard to figure out what keywords to use, but you need to start somewhere. I usually take a wild stab at what keywords I should focus on and then input them into the Overture Keyword Selector Tool.
This tool was set up so that Overture customers could determine the inventory of keywords for their advertisements. But it works just as well for SEO purposes. Simply enter your keywords into the box and hit enter.
My first guess at good keywords was "Internet safety".